Range detection systems, such as LiDAR, can be used to collect three dimensional images of a scene. A scene, as used herein, is a contiguous portion of a physical space accessible to being viewed. Typically, a laser beam or multiple beams are scanned across the scene in a raster scan fashion. Optical pulses are transmitted at timed intervals. A collector of backscattered light reflected off of objects in the scene focuses the light onto a photosensitive detector. The signal produce by the detector is analyzed to determine time of arrival so that the distance can be calculated based on the total round trip time of the pulse. The raster scan repeatedly repositions the scan back and forth across the scene so as to produce a three dimensional mapping of the scene. The mapping is a representation of the geometric shape of the scene in spherical coordinates originating at the sensor. Trigonometric functions can be used to convert the image to Cartesian coordinates.
The mechanics required to rapidly scan back and forth across the scene can be complex, expensive and subject to performance degrading wear and tear. A variety of mechanical options have been developed for laser scanning. These include mechanically operated translational stages, adjustable prisms and adjustable mirrors.